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The history of crustal uplift and metamorphic evolution of Panzhihua-Xichang micro-palaeoland, SW china:Constraints on Sm-Nd, ^(40)Ar/^(39)Ar and FT ages of granulites

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Science china Earth Sciences 2004年第8期47卷 689-703页

作者： XU Shijin1, LIU Wenzhong1, WANG Rucheng1, YU Hangbo1, LI Daming2. WAN Jinglin2.& FANG Zhong1 1. Department of Earth Sciences and State Key Laboratory for Mineral Deposits Research, Nanjing University, Nanjing 2.0093, china 2. institute of Geology,{2., beijing 10002., china Department of Earth Sciences and State Key Laboratory for Mineral Deposits Research Nanjing University Nanjing China institute of Geology China Seismological Bureau Beijing China

Panzhihua-Xichang (Panxi) micro-palaeoland is the oldest terrane on the western margin of the Yangtze Block. Some intermediate-basic granulites are considered to be the crys-talline basement of lower crust in the terrane. Granulite-facies metamorphism of the granulites was developed in the period from 1186 Ma to 112. Ma. The origin of granulites was related to the collision orogenic process occurring when the micro-palaeolands merged to form the Rodinia Supercontinent. Amphibolite-facies retrogressive metamorphism of granulites took place in the period from 877 Ma to 82. Ma. This period was consistent with the breakup time of the Rodinia Supercontinent. 40Ar/39Ar ages and fission track (FT) ages of granulites in the Panxi mi-cro-palaeoland show that the vertical movement history of crustal rocks was a slow uplift process of the rigid terrane in the time from Neoproterozoic to Mesozoic. The subduction of India Plate towards Euroasia Plate resulted in the rapid uplift of the Qinghai-Tibetan Block in Cenozoic. Meanwhile, the Qinghai-Tibetan Block moved towards east. Consequently the Panxi terrane was uplifted rapidly. As a result of the collision orogeny between the Qinghai-Tibetan Block and the Panxi terrane, the granulite-facies crystalline basement in this region was exhumed and exposed to the surface.

关键词： granulite,isotope geochronology,crustal uplift movement,Panzhihua-Xichang region,western margin of Yangtze Block.

Magma underplating and Hannuoba present crust-mantle transitional zone composition: Xenolith petrological and geochemical evidence

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Science china Earth Sciences 2005年第8期48卷 1089-1105页

作者： FAN Qicheng1,2. ZHANG Hongfu1, SUI Jianli1, ZHAI Mingguo1, SUN Qian2.& LI Ni2.1. institute of Geology and Geophysics, Chinese Academy of Sciences, beijing 10002.,{2. 2. institute of Geology, china seismological bureau, beijing 10002.,{2. institute of Geology and Geophysics Chinese Academy of Sciences Beijing China institute of Geology China Seismological Bureau Beijing China

On the basis of mineral assemblage, mineralogy, petrology, and major, trace ele-mental and isotopic geochemistry of the underplated granulite- and eclogite-facies accumulate, peridotite and pyroxenite xenoliths entrained in Hannuoba Cenozoic basalts, this work con-strained the petrological constituents for the crust-mantle transitional zone, which is supported by the results of high-temperature and pressure velocity experiments on rocks and geophysics deep survey. Present lower part of lower crust is mainly composed of granulite-facies mafic accumu-lates (dominantly plagioclase websterite) and crust-mantle transitional zone dominantly com-posed of eclogite-facies pyroxenites with or without garnet and spinel lherzolites; Archaean ter-rain granulite is only nominally early lower crust. Magma underplating in the crust-mantle boundary led to the crustal vertical accretion and the formation of the crust-mantle transitional zone, which is a significant mechanism for the chemical adjustment of the crust-mantle boundary since the Phanerozoic.

关键词： magma underplating, xenolith petrology, geochemistry, cust-mantle boundary constituent, Hannuoba.

The crustal structure under Sanjiang and its dynamic implications:Revealed by seismic reflection/refraction profile between Zhefang and Binchuan,Yunnan

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Science china Earth Sciences 2005年第9期48卷 1329-1336页

作者： ZHANG Zhongjie1, BAI Zhiming1, WANG Chunyong2. TENG Jiwen1, Lü Qingtian3, LI Jiliang1, LIU Yifeng1 & LIU Zhenkuan4 1. institute of Geology and Geophysics, Chinese Academy of Sciences, beijing 10002.,{2. 2. institute of Geophysics, china seismological bureau, beijing 100085,{2. 3. institute of Deposition Resource, Chinese Academy of Geosciences, beijing 100037,{2. 4. School of Exploration and Information,{2. University of Geosciences, beijing 100083,{2. institute of Geology and Geophysics Chinese Academy of Sciences Beijing China institute of Geophysics China Seismological Bureau Beijing China institute of Deposition Resource Chinese Academy of Geosciences Beijing China School of Exploration and Information China University of Geosciences Beijing China

The fault belts in Sanjiang mainly include Jinshajiang-Honghe fault, Lancangjiang fault and Nujiang fault (called Sanjiang faults) in western Yunnan Province, china. By interpreting the wide-angle seismic reflection/refraction profile between Zhefang and Binchuan, which crosses Tengchong and Baoshan blocks in Dianxi (western Yunnan) tectonic zone, we recon- struct the crustal structure with seismic traveltime tomography for crustal P-wave velocity and the seismic scattering image for crustal seismic reflection structure. In this paper, we firstly present the crustal structure images of P-wave velocity and seismic reflection under the wide-angle seismic profile. These results demonstrate that, the crustal velocity structure and seismic reflec- tion structure along the profile can be divided into 3 segments, and there is an obvious difference of crustal structure among the eastern, the western and the middle segment. Generally, crustal P-wave velocities in the Baoshan segment are 0.1―0.2.km/s slower and seismic reflection am- plitudes from Moho discontinuity are stronger than the other 2.segments. In the studied area, crustal thickness is about 40 km, and shows the thickening tendency from west to east along the profile. Additionally, it can be seen that there is one strong-amplitude seismic reflection event as bright points at the depths of 8―10 km, along the segment of 80―115 km of the profile (south- ward of Tengchong); and seismic reflection wave-field from Moho discontinuity varies obviously along the lateral direction. Finally, we make some discussions on the crustal thickening pattern in the Sanjiang fault belt, structural environment of earthquake development and the contact rela- tionship between the Tengchong block, Banshan block and Luxi trough.

关键词： Sanjiang area wide-angle seismic profile crustal structure.

Si-and alkali-rich melt inclusions in minerals of mantle peridotites from eastern china:Implication for lithospheric evolution

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Science china Earth Sciences 2006年第1期49卷 43-49页

作者： FAN Qicheng1, SUI Jianli2. XU Ping2. LI Ni1, SUN Qian1 & WANG Tuanhua1 1. institute of Geology, china seismological bureau, {2. 10002., china 2. institute of Geology and Geophysics, Chinese Academy of Sciences, {2. 10002., china institute of Geology China Seismological Bureau Beijing China institute of Geology and Geophysics Chinese Academy of Sciences Beijing China

Minerals of spinel- and garnet-facies mantle xenoliths entrained in Cenozoicbasalts from eastern china (North china, Northeastern china and Southeastern china coastal area)contains lots of melt inclusions. Studies on these melt inclusions show that the glass inclusionsare rich in SiO_2.(60%—68%) and alkalis (K_2.+Na_2. = 5%—11%, especially for K_2.) as well asvolatiles such as H_2. and CO_2.(2.—7%), which belong to dacites and andesites of the high-K calcicalkali series rocks with few shoshonites. High Al and Ca diopside in melt inclusion is the productof melt crystallization at high temperature and pressure, rather than the product ofdevitrification. Results show that these K-rich (in general K_2. > 3%) intermediate-acidic silicatemelt inclusions have characteristics of continent without a genetical link to host basalts and theirphenocrystic minerals. Thus, these trapped melt inclusions represent melts of Mesozoic lithosphericmantle-crust interaction and imply that the continental lithospheric mantle beneath eastern chinahad undergone fragmentation and recreation processes during the Mesozoic and Cenozoic periods. Thisresult undoubtly provides important implication for the evolution of sub-continental lithospherebeneath eastern china. We propose that these Si- and alkalis-rich melts should be responsible forthe mantle chemical heterogeneity underneath eastern china.

关键词： Si- and alkali-rich melt inclusion, mantle peridotite, lithospheric evolution, eastern china.

Research progress in synthesis and catalysis of polyoxometalates

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Progress in Natural Science:Materials International 2005年第5期15卷 385-394页

作者： GONG Yun1, HU Changwen1* and LIANG Hong2.1. Department of Chemistry, School of Science, the institute for Chemical Physics, beijing institute of Technology, beijing 100081, china 2. Chemical Industry Press, beijing 10002., china) Sch. of Sci Inst. for Chem. Phys. Beijing Inst. of Technol. Beijing 100081 China Chem. Indust. Press Beijing 100029 China

Recent progress in the synthetic chemistry and catalysis of polyoxometalates (POMs) is reviewed. The novel POMs and their derivatives emerging in nearly three years (2.02.2.04) are introduced, including POMs with novel structure, POMs-organic hybrid compounds and host-guest complexes. Our review is focused on the elaboration of POMs' supramolecular chemistry.

关键词： polyoxometalates hybrid host-guest structure supramolecule catalysis.

Pattern phenomena in an rf discharge dusty plasma system

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Science china(Physics,Mechanics & Astronomy) 2006年第5期49卷 588-596页

作者： HUANG Feng1,2. YE Maofu2.& WANG Long2.1. College of Science, china Agricultural University, beijing 100083, china 2. institute of Physics, Chinese Academy of Sciences, beijing 100080, china College of Science China Agricultural University Beijing China institute of Physics Chinese Academy of Sciences Beijing China

Various dust patterns are observed in an rf discharge dusty plasma system. According to the dust growth process from small to large in size, the formation of different dust patterns can be divided into two stages: the small-particle stage (or dust cloud stage), and the large-particle stage (or dust crystal stage). The evolution relations between different dust patterns with gas pressure changing are investigated. Dust voids, dust acoustic waves and strong turbulence modes are presented at the small-particle stage. The self-organized dust lattices and dust clusters are investigated at the large-particle stage. The static structure of a dust lattice is characterized by means of the pair correlation function. Dust clusters formed by particles with different numbers and the regular evolution of the clusters with gas pressure are also investigated. The packing sequences of dust clusters are verified through two-dimensional confined molecular dynamics simulations.

关键词： dusty plasma dust patterns

Mineralogy and crystal structure determination of Mg-fillowite

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Science china Earth Sciences 2005年第5期48卷 635-646页

作者： MA Zhesheng 1 , SHI Nicheng 1 & YE Danian 2.1. china University of Geosciences, beijing 100083, china 2. institute of Geology, Chinese Academy of Sciences, beijing 10002., china china University of Geosciences Beijing China institute of Geology Chinese Academy of Sciences Beijing China

Accurate crystal structure determination of complex phosphate Mg-fillowite ? Na2.a(Mn4Mg2.e)7[PO4]6 has been finished. Mg-fillowite occurs in muscovite-pegmatite in the Altay area, Xinjiang, china. It is of the trigonal lattice, with space group R-3, unit cell a=1.5143(3) nm, c=4.3191(2. nm, V=8.5736 nm3, Z = 18. The R-factor of the determination accuracy is R (I > 2. ( I )) = 0.0776. The cationic polyhedra consist of two kinds of structural units: compound col- umn and screw column. In three-dimensional space, they are linked with each other through corner sharing or edge sharing to build the entire structure. There are 45 atoms in an asymmetric unit and 72. atoms in a unit cell. In terms of types and connection manners of the coordination polyhedra, the degree of complicity is rarely seen in all mineral crystal structures. Study of such a structure is significant for the classification of phosphate and the building rule of coordination polyhedra in a complex crystal structure.

关键词： Mg-fillowite, complex phosphate, crystal structure, coordination polyhedron.

The numerical method for three-dimensional impact with friction of multi-rigid-body system

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Science china(Physics,Mechanics & Astronomy) 2006年第1期49卷 102-118页

作者： ZHAO Zhen1,2. LIU Caishan2.& CHEN Bin2.1. beijing institute of Graphic Communication, beijing 102.00, china 2. Department of Mechanics & Engineering Science, Peking University, beijing 100871, china beijing institute of Graphic Communication Beijing China Department of Mechanics & Engineering Science Peking University Beijing China

The differential equations for planar impacts reduce to an algebraic form, and can be easily solved. For three dimensional impacts with friction, there is no closed-form solution, and numerical integration is required due to the swerve behavior of tangential impulse during collisions. The dynamic governing equations in the impact process are built up in impulse space based on the Lagrangian equation in this paper. The coefficient of restitution defined by Poisson is used as the condition of impact termination. A valid nu- merical method for solving three-dimensional frictional impact of multi-rigid body system is established. The singular cases of tangential movement in sticking point are especially noticed and analyzed. Several examples are present to reveal the different kinds of tan- gential movement modes varied with the normal impulse during collision.

关键词： multi-rigid body, impact, friction.

Randomization of protein encoding gene during species evolution

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Chinese Science Bulletin 1998年第4期43卷 299-303页

作者： GE Weiwen 1 and HE Fuchu 2.1. institute of Hygiene and Environment Medicine, Tianjin 300050, china 2. institute of Radiation Medicine, beijing 100850, china institute of Hygiene and Environment Medicine Tianjin China institute of Radiation Medicine Beijing China

Employing chi_square test, the authors observed the bias of 4 kinds of bases’ locating in 3 codon positions in gene sequence, and proved that there is a positive correlation between higher chi_square value and protein coding structure. By this, the observation that genes undergo progressive reduction in chi_values along evolution direction will reflect the progressive randomization of gene structures and the loss of the characteristics of protein coding sequences. The result proposed that during the evolution of life, genes are unexpectedly degenerating.

关键词： chi_square test gene sequence randomization evolution.